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Atlantic hurricane season shows signs of life

After a slow start, developments are taking place in the east of the Basin.

29 Jul 2016 09:03 GMT

Hurricane Alex hit Mexico In January, but since then, storm development has been minimal.[EPA]

It could be argued that the 2016 hurricane season got off to a spectacular start, with the formation of Hurricane Alex, the first January hurricane since 1938.

Really, Alex was a throwback to 2015 and the still strong El Nino.

The official start of the hurricane season is 1 June and it runs through until 30 November, but Mother Nature does not take too much notice of the calendar.

Since Alex, we have seen just three Tropical Storms: Bonnie in May, and Colin and Danielle, in June. In itself that is not surprising, as June and July combined only account for 14 percent of the season’s named storms.

Now, we have a cluster of showers sitting off the coast of West Africa, south of the Cape Verde Islands which is showing signs of development.

There are no signs that the current mass of showers off the coast of West Africa will attain hurricane status. Nevertheless, current conditions are favourable for some growth.

Sea surface temperatures need to be at least 26.5C and they are currently around 28C. The vertical winds through the atmosphere, known as wind shear, are also light enough to encourage development.

Acting against that, there is lots of dry Saharan dust blowing across the Atlantic. This combined with stronger wind shear, and cooler seas across the central Atlantic, mean that even if this storm cluster develops into a named storm (Earl), it will be nothing more than a ‘fish storm’ remaining over open water.

A July hurricane occurs, on average, only once every two to three years; and only five major hurricanes (Category 3 or above on the five point Saffir-Simpson scale) have occurred in this month since 1950.

It is a long and perilous journey for any developing system originating near the coast of West Africa. This is why most storms in the early part of the season are much more likely to form much closer to the Caribbean region.

A change is usually expected in late August and September, when the hurricane season usually sparks into life. In an average Atlantic season, we expect 12.1 named storms, 6.4 hurricanes and 2.7 major hurricanes. Most hurricane forecasting centres, predict normal to slightly above normal activity for 2016.